Solid storable and non-foaming bottle cleansing agents



United States Patent T H 54,12 Int. Cl. Clld 7/ 06'; B08b 3/08 US. Cl. 252-156 4 Claims ABSTRACT OF THE DISCLOSURE A substantially non-foaming and storable bottle cleansing agent which contains 50 to 95 percent caustic alkali of a grain size of less than 3 mm. and 0.5 to 3.5 percent of a propylene oxide adduct on an aliphatic polyalcohol having at least four hydroxyl groups and a cloud point from 10 to 50 C. The balance of the compound is made up of orthoor polyphosphates, soda, potash, gluconates, sodium silicate and fillers.

The invention relates to highly alkaline bottle cleansing agents which are storable for long periods of time and which have the property of suppressing foam in the deans ing solution. More particularly, it relates to agents consisting to a large extent of fine-grained caustic alkali of a given particle size, plus an additive consisting of certain reaction products of propylene oxide.

The use of alkaline bottle cleansing agents is known which, beside fairly large quantities of caustic alkali, contain such ingredients as orthoand polyphosphates, gluconates, silicates and, in some instances, wetting agents. Especially in automatic bottle cleansing devices, foam suppressants also are added. The latter not only are to avert an overflow of the liquid due to foaming, but also to facilitate the removal of labels stripped off the bottles in order to avoid shutdowns.

It also is known that foam suppressants are of different efiicacy depending upon the source of the foam. The latter may come into being in many different ways in bottle cleansing processes. Label adhesives preferably are dextrin or casein glue which produce foam. Chain lubricants and printing inks introduce wetting agents of several kinds, particularly alkylbenzene sulfonates or soaps. Residual bottle contents, such as soft drinks, milk or beer, also give rise to foam formation.

It therefore has met with difiiculties to find foam suppressants which are active for all the foams named. In practice, nonionic compounds frequently are used, e.g.,

addition products of ethylene oxide on fatty alcohols or fatty amines, but these, also, are of limited effectiveness. Most important, these compounds cannot be incorporated in bottle cleansing agents containing powdered caustic alkali because they lose their effectiveness entirely in the presence of finely powdered caustic alkali, and the originally non-foaming bottle cleansers, within a short period of time, convert into strongly foaming materials.

Attempts at substituting coarsely flaked alkali for the powder, in order to slow the decrease in effectiveness, have not met with success at higher alkali contents, alone on account of separation of the ingredients.

It now has been found that these drawbacks are avoided when bottle cleansing agents are employed as hereinafter described which preferably have an alkali content of 50-95 percent. The agents according to the invention are characterized by a content of (a) caustic alkali having 3,491,029 Patented Jan. 20, 1970 a grain or particle size of less than 3 mm. diameter and (b) reaction products of propylene oxide with aliphatic polyalcohols whose cloud point is between 10 and C., preferably btween 15 and 40 C.

The fine-grained caustic alkali content enables ready manufacture of powdered bottle cleansing agents which exhibit no separation, not even upon storage, refilling or transportation. The alkali used may be powdered or finely grained whereby the particle size must not be more than 3 mm. and preferably more than percent should be of a particle size of less than 1.5 mm. Upon the use of coarse grains, separation may occur. The preferred caustic alkalis are sodiumand potassium hydroxide.

Preferred reaction products of propylene oxide with polyalcohols are those with polyalcohols of 4 or more hydroxyl groups in their molecules. Particularly effective regarding lowering of the foam volume of the cleansing agents are reaction products with pentaerythritol and dipentaerythritol.

Especially advantageous is the employment of the reaction product of propylene oxide with polyglycerol which is an inexpensixe byproduct of the glycerol manufacture. In that manufacture on a production scale a still bottom remains consisting of a mixture of higher-molecular condensation products of glycerol, usually ranging from 2 to 10 glycerol radicals per molecule. The polyglycerols are characterized by their OH value which preferably lies between 900 and 1,200. The corresponding polyglycerols also can be produced synthetically. According to the invention, preferably reaction products of propylene oxide with polyglycerol are used whose cloud point lies between 20 and 35 C.

These reaction products preferably are employed in quantities of 0.5 to 3.5%, calculated on the total solid bottle cleansing agent.

In order to attain the cloud point range of 10 to 50 C.

named above, a definite number of propylene oxide groups must be added to the polyalcohols. This number depends upon the kind of polyalcohol used. The cloud point generally becomes lower with increasing amounts of propylene oxide groups. The cloud point is determined in each instance by slow heating of a 1 percent aqueous solution and determination of the first clearly discernible cloudiness. The cloud points given refer to pure solutions. The addition of foreign matter varies the cloud points. The bottle cleansing agents according to the invention may contain, aside from the principal ingredients, i.e., caustic alkali and propylene oxide-polyalcohol reaction products, the customarily used additives, such as orthophosphates, polymeric phosphates, soda, potash, gluconates, and, if desired, wetting agents. The agents are employed in the customary bath concentrations of 0.1 to 2 percent, and preferably of 0.5 to 1 percent. The most favorable application temperature is 60 to C.

The bottle cleansing agents according to the invention can be stored for long periods of time. They do not change their foam-depressing properties and are effective against all kinds of foams occurring in bottle washing processes.

The invention now will be further explained by the following examples.

However, it should be understood that these are given merely by way of illustration, and not of limitation, and that numerous changes may be made in the detail without departing from the spirit and the scope of the invention as hereinafter claimed.

All percentages in this specification are percent by weight unless otherwise specified.

3 EXAMPLE 1 The storability of the reaction products of propylene oxide with polyalcohol in the presence of solid finely grained caustic alkali was determined as follows:

98% finely powdered NaOH Were mixed intimately with 2% of the substance to be tested in a high-speed mixer and then stored at room temperature. Within a period of 3 months, the cloud point of these mixtures was determined every 3 weeks in 1% aqueous solution. The determination of the cloud point was carried out by slow heating of the solution and noting the temperature at which the first discernible clouding of the solution occurred. Those mixtures whose cloud point did not vary were considered stable upon storage. Decomposition of the substance gave rise to an increase in the cloud point temperature. The results are listed in Table 1. For purposes of comparison, a reaction product of ethylene oxide with polypropyleneglycol was tested.

Like results were obtained when, in lieu of NaOH,

EXAMPLE 2 The reduction of the foam volume of cleansing solutions by the agents according to the invention was determined in the following manner:

The alkali solutions used were produced by refluxing of 3% NaOH solution in water with different additives for hours. As additives the following were used: 3% of a commercial dextrin glue; 3% of a commercial casein glue; 3% milk; 0.075% tetrapropylenebenzenesulfonate (100%); 0.1% curd soap. 100 ml. each of these solutions were heated to 60 and 80 C., respectively, in a measuring cylinder and then strongly shaken therein times. The foam volume thus created was read in ml. immediately after shaking. For the determination of the stability of the foam produced, the foam volume again was read after 30 and 60 seconds. The results are found in Table 2.

Like tests were carried out with the sole difference that to the solutions, prior to refluxing, 0.045 volume percent of the following substances were added:

The reaction product of pentaerythritol with 20 mols propylene oxide (cloud point 30 C.);

The reaction product of dipentaerythritol with 20 mols propylene oxide (cloud point 37 C.);

The reaction product of polyglycerol (OH value 1,060) with 6.6 mols propylene Oxide per OH group (cloud point 26.5 C.).

The foam volumes found are listed in Table 2.

EXAMPLE 3 A bottle cleansing agent was prepared by mixing the following compounds:

Percent NaOH (grain size less than 2 mm.) 85

Polyphosphate 10 Sodium silicate (Na O:SiO =3.35) 3.5 Reaction product of polyglycerol (OH value 1,040) with 6.6 mols propylene oxide-OH group (cloud point 26 C.) 1.5

This material was stored for 6 months before using it in an automatic bottle washing machine at C. It exhibited excellent cleansing action and very little foam formation. Beer-, milkand soft drink bottles, some of which had paper labels, were entirely clean after the wash, the labels came off easily and could be removed from the machine without difficulty.

EXAMPLE 4 A bottle cleansing agent was produced by mixing the following compounds:

Percent KOH (grain size less than 1.5 mm.) 60 Polymeric phosphate 20 Sodium silicate (Na O:SiO =3.35) 7 Filler (Na SO 10 Reaction product of polyglycerol (OH value 1,010) with 5.2 mols propylene oxide per OH group (cloud point 32 C.) 3

This compound was stored for 6 months and then used in an automatic bottle washing machine at 80 C. Beer-, soft drinkand milk bottles were entirely clean after the treatment. Some bore labels which came off and could readily be removed. Foam development was negligible.

EXAMPLE 5 A bottle cleanser was produced by mixing the following materials:

Percent NaOH (grain size less than 2 mm.)

Polymeric phosphate 15 Sodium silicate (Na O:SiO =3.35) 8 Reaction product of dipentaerythritol with 20 mols propylene oxide (cloud point 37 C.) 2

After a 6 months storage period, beer-, soft drinkand milk bottles, some of which were provided with paper labels, were washed at C. in an automatic bottle washing machine. The bottles were entirely clean after the wash, foam development was very slight, and the labels which had come off, could readily be removed.

TABLE 2.FOAM VOLUME AFTER 20 SHAKES (1111.)

No additive (blank) Pentaerythritol+20 PO 1 (OP 2 305 C.)

Dipentaerythritol +20 PO Polyglycerol +5.5 PO/OH (OP 37 C.) (OP 26.5" 0.)

S01. Temp. C.) No. 0 30 30 O 30 60 0 30 60" 0 30 60" 60 1 70 50 5 0 0 10 5 0 0 0 0 2 250 50 25 15 15 10 25 20 15 2O 15 15 3 400 280 250 5 5 0 65 55 50 4 250 200 180 15 15 10 25 20 20 165 65 65 5 250 150 100 50 35 20 80 70 50 8O 1 50 45 45 5 0 0 5 0 O 0 0 0 2 295 195 100 25 20 15 10 5 5 5 5 5 3 400 350 225 0 0 0 50 40 35 4 155 100 25 25 20 20 20 15 40 35 5 300 200 150 45 40 25 20 45 40 30 1 P0 =mo1s propylene oxide. 2 CP=cloud point.

3 Solutions were 3% aqueous NaOH containing the following additives:

Solution 1: 3% dextrin glue.

Solution 2: 3% casein glue.

Solution 3: 3% milk.

Solution 4: 0.075% tetrapropylenebenzene sulionate (100%). So u i n 5 0 uisoap- We claim as our invention:

1. A highly alkaline, storable and substantially nonfoaming bottle cleansing agent, in solid form, consisting essentially of a caustic alkali, said alkali being present in a quantity of approximately 50 to 95% of the total composition and said alkali having a grain size of less than 3 mm.; a propylene oxide adduct on a polyalcohol selected from the group consisting of pentaerythritol, dipentaerythritol and polylglycerol having an OH value of substantially 900-1200, said adduct having a cloud point ranging from to 50 C. and said adduct being present in an amount of approximately 0.5 to 3.5% calculated on the total composition.

2. A solid, substantially non-foaming, storable, bottle cleansing agent consisting essentially of approximately 50 to 90% finely grained caustic alkali having a particle size of less than 3 mm., calculated on the total composition; and approximately 0.5-3.5%, calculated on the total compositon, of a propylene oxide adduct on a polyalcohol selected from the group consisting of pentaerythritol, dipentaerythritol and poly-glycerol of an OH value of substantially 900 to 1200, said adduct having a cloud point of 10 to 50 C.; the balance of said agent being selected from the group consisting of soda, potash, sodium silicate and sodium sulfate.

3. A process for washing bottles which comprises subjecting said bottles to a stream of a 0.1 to 0.2% aqueous solution at substantially 60 to 80 C., said solution consisting essentially of approximately 50 to 95%, calculated on the total composition, of finely grained caustic alkali having a grain size of less than 3 mm., and approximate- UNITED STATES PATENTS 2,454,541 11/1948 Bock et a1. 25289 2,463,680 3/1949 Corrigan 252-156 2,554,667 5/1 951 De Groote.

2,555,285 5/1951 Black 25289 2,584,017 1/1952 Dvorkovitz et al. 252156 2,976,248 3/1961 Othralek 252156 3,031,510 4/1962 Crecelius 25289 3,128,314 4/1964 Shen et al 25289 3,317,508 5/ 1967 Winquist et al.

LEON D. ROSDOL, Primary Examiner W. SCHULZ, Assistant Examiner US. Cl. X.R. 

